1. Field
The present disclosure relates to zoom lens systems, imaging devices, and cameras.
2. Description of the Related Art
With recent progress in the development of solid-state image sensors such as high-definition CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor), digital still cameras and digital video cameras (simply referred to as “digital cameras”, hereinafter) are rapidly spreading which employ an imaging device including an imaging optical system of high optical performance corresponding to the above-mentioned high-definition solid-state image sensors. Among the digital cameras of high optical performance, in particular, from a convenience point of view, compact digital cameras are strongly desired which employ a zoom lens system having a high zooming ratio and covering, by itself, a wide focal-length range from a wide angle condition to a highly telephoto condition. Furthermore, compact digital cameras are desired which employ a zoom lens system having a wide angle range where a photographing field is large.
Various kinds of zoom lens systems as follows have been proposed for use in the compact digital cameras.
Japanese Laid-Open Patent Publications Nos. 2009-075581, 2009-150970, 2007-264390, 2007-264173, 08-220439, 08-043734, and 07-151975, and Japanese Patent No. 4840354 each disclose a zoom lens having five lens units of positive, negative, positive, positive, and negative in order from an object side to an image side.